8,704 research outputs found
Generalized L\"uscher's Formula in Multichannel Baryon-Baryon Scattering
In this paper, L\"uscher's formula is generalized to the case of two
spin- particles in two-channel scattering based on Ref.
\cite{Li:2012bi}. This is first done in a non-relativistic quantum mechanics
model and then generalized to quantum field theory. We show that L\"uscher's
formula obtained from these two different methods are equivalent up to terms
that are exponentially suppressed in the box size. This formalism can be
readily applied to future lattice QCD calculations.Comment: Introduction expanded and references added. 10 pages, no figure
The Framing of China\u27s Bird Flu Epidemic by U.S. Newspapers Influencial in China: How the New York Times and The Washington Post Linked the Image of the Nation to the Handling of the Disease
This study conducted a framing research that analyzed coverage of the bird flu (avian flu) in China by two major American newspapers that are influential in China (The New York Times and Washington Post). The goal was to examine how these two prestigious newspapers frame the bird flu epidemic in China and how they represent the country in this international health crisis. This study employed textual analysis regarding the way bird flu news articles were framed in terms of problem definition, causal explanation, moral evaluation and solution recommendations in both newspapers. The study found the epidemic was framed as more than just a public health crisis. Multiple news frames were found in both newspapers\u27 coverage of bird flu, depicting the event as a cultural, social and political crisis to the nation and to the world
The meson-exchange model for the interaction
In the present work, we apply the one-boson-exchange potential (OBEP) model
to investigate the possibility of Y(2175) and as bound states of
and respectively.
We consider the effective potential from the pseudoscalar -exchange and
-exchange, the scalar -exchange, and the vector
-exchange and -exchange. The and meson exchange
potential is repulsive force for the state and attractive for .
The results depend very sensitively on the cutoff parameter of the
-exchange () and least sensitively on that of the
-exchange (). Our result suggests the possible
interpretation of Y(2175) and as the bound states of
and respectively
Discriminative Nonparametric Latent Feature Relational Models with Data Augmentation
We present a discriminative nonparametric latent feature relational model
(LFRM) for link prediction to automatically infer the dimensionality of latent
features. Under the generic RegBayes (regularized Bayesian inference)
framework, we handily incorporate the prediction loss with probabilistic
inference of a Bayesian model; set distinct regularization parameters for
different types of links to handle the imbalance issue in real networks; and
unify the analysis of both the smooth logistic log-loss and the piecewise
linear hinge loss. For the nonconjugate posterior inference, we present a
simple Gibbs sampler via data augmentation, without making restricting
assumptions as done in variational methods. We further develop an approximate
sampler using stochastic gradient Langevin dynamics to handle large networks
with hundreds of thousands of entities and millions of links, orders of
magnitude larger than what existing LFRM models can process. Extensive studies
on various real networks show promising performance.Comment: Accepted by AAAI 201
Shape memory alloy actuated adaptive exhaust nozzle for jet engine
The proposed adaptive exhaust nozzle features an innovative use of the shape memory alloy (SMA) actuators for actively control of the opening area of the exhaust nozzle for jet engines. The SMA actuators remotely control the opening area of the exhaust nozzle through a set of mechanism. An important advantage of using SMA actuators is the reduction of weight of the actuator system for variable area exhaust nozzle. Another advantage is that the SMA actuator can be activated using the heat from the exhaust and eliminate the need of other energy source. A prototype has been designed and fabricated. The functionality of the proposed SMA actuated adaptive exhaust nozzle is verified in the open-loop tests
The Photosynthetic Characteristics of Wild <em>Cymbidium faberi</em> in the Qinling Mountains of Central China
The large flowers of orchids make them popular as cultivated plants. Seven species of orchids in the genus Cymbidium (Orchidaceae) have been crossbred to create more than 220 hybrids that serve as popular cultivated ornamentals. The present study examined the daily variation in the patterns of the net photosynthetic rate and the photosynthetic response of wild Cymbidium faberi in the Qinling Mountains in northwestern China. The photosynthetic characteristics of this species were studied under natural conditions with a portable photosynthesis system. Double peaks were observed in the net photosynthetic rate with one around 09:00 and another around 17:00 in spring, as well as one around 11:00 and another around 15:00 in winter. Midday depression of photosynthesis was observed in wild C. faberi plants around 13:00 in both spring and winter. The net photosynthetic rate was strongly positively correlated with both stomatal conductance (R = 0.913) and the transpiration rate (R = 0.659) and weakly negatively correlated with the intercellular carbon dioxide concentration (R = −0.094). The results show that the light compensation point (LCP) and the light saturation point (LSP) of wild C. faberi were 25.78 and 384 μmol m−2 s−1, respectively. The result provides reference for cultivation management especially in light management of Cymbidium
On the Anonymity of Identity-Based Encryption
Anonymity of identity-based encryption (IBE) means that given a ciphertext, one cannot distinguish the target identity from a random identity. In this paper, we thoroughly discuss the anonymity of IBE systems. We found that the current definition of anonymity is obscure to describe some IBE systems, such as Gentry IBE system. Furthermore, current definition cannot express the degree of anonymity. So we divide the degree of anonymity into weak anonymity and strong anonymity based on indistinguishability between different games. For weakly anonymous IBE systems, the target identity in a ciphertext cannot be distinguished from a random identity. For strongly anonymous IBE systems, the whole ciphertext cannot be distinguished from a random tuple. We also discuss the type of anonymity and divide it into two types. Type 1 means that a random tuple can be seen as a valid ciphertext, while type 2 cannot. Based on our new definitions, we show that three famous IBE systems, Gentry IBE system, Boyen-Waters IBE system, and Lewko IBE system, have strong but different types of anonymity
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